Transanal endoscopic surgery with a 3D printed device.

Background: The aim of this study was to investigate the effectiveness of devices manufactured with 3D printing for performing transanal endoscopic procedures without pneumorectum.
Methods: Functional devices were designed in the Polytechnic School of Engineering of Gijón from 2016 to 2018 using three-dimensional (3D) solid modelling software (Solid-Works®), that allows customization of the device (diameter and length). The devices were made in acrylonitrile butadiene styrene (ABS) by additive manufacturing using an HP Designjet 3D Printer, with fused deposition modelling (FDM) technology. Tests were carried out on mixed simulators (with viscera) and cadavers with a prototype in the form of an open cylindrical base ellipsoid spindle with two bars. In this paper, we present the information of the first series of patients in which this device has been used to perform a full-thikness endoscopic resection of the rectal wall without pneumorectum. The characteristics of the patients, size, and location of the lesion, the type of anesthesia used, the duration of the procedure, hospital stay, complications, and pathology were analyzed. An endoscopic follow-up was also carried out for at least 2 years.
Results: Seven interventions were carried out in six patients. The lesions were located at a mean distance of 5 cm from the anal verge and an average area of 11.8 cm ² . Four of the procedures were performed with general anesthesia and 3 with spinal anesthesia. Histopathology examination identified 3 adenomas, 3 pT1 and 1 pT2 adenocarcinomas. All excisions were full thickness. En bloc excision was possible in all cases. In only one case of a benign polyp there was a positive lateral margin. As regards complications, there was one case of postoperative rectal bleeding without the need for transfusions. There were no readmissions and no postoperative mortality.
Conclusions: An innovative device made with a 3D printer can be used successfully in transanal endoscopic resections of the rectal wall, with spinal anaesthesia and avoiding the need for pneumorectum.
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